I. Field of the Invention
The present disclosure relates generally to the fields of chemistry and materials science. More particularly, it concerns metal-organic frameworks with open metal sites, compositions thereof and methods use thereof, including acetylene storage.
II. Description of Related Art
Acetylene is a very important raw material for various industrial chemicals, consumer products and for oxy-acetylene cutting in metal fabrication shops. The realization of improvements in high-density acetylene storage media are desirable. Suitable goals include increased storage capacity, safer handling, storage and transportation (Stang and Diederich, 1995; Chien, 1984).
With the realization of open structures and permanent porosity in some prototype metal-organic frameworks (MOFs) such as MOF-5 and HKUST-1 (Li et al., 1999; Chui et al., 1999), research attention have been paid to the implementation of functional sites within MOFs for their specific recognition and thus functional properties. By immobilizing open metal sites, Lewis acidic and basic sites into the pore surfaces of MOFs, a series of unique MOFs have been developed for gas storage, separation, catalysis and sensing (Rieter et al., 2008; Chandler et al., 2006; Mulfort and Hupp, 2007; Lan et al., 2009; Yildirim and Hartman, 2005; Peterson et al., 2006; Dinca et al., 2006; Zhou and Yildirim, 2008; Zhou et al., 2008; Wu et al., 2009; Liu et al., 2008; Ma et al., 2008; Caskey et al., 2008; Zhang et al., 2008; Lin et al., 2009; Xiao et al., 2007; Chen et al., 2008a; Chen et al., 2008b Couck et al., 2009). Because of the very explosive nature of acetylene, the nature of the interaction between specific sites within porous materials and acetylene molecules may be important for to achieve high acetylene storage at room temperature and under a pressure of 0.2 MPa (the compression limit for the safe storage of acetylene) (Budavari, 1996).
Previous efforts on porous materials and MOFs for acetylene storage have been mainly focused on those with small pores to enhance their acetylene adsorption enthalpies which have limited their uptake capacities, with the highest one of 106 cm3/g ever reported (Reid and Thomas, 1999; Reid and Thomas, 2001; Matsuda et al., 2005; Thallapally et al., 2006; Samsonenko et al., 2007; Tanaka et al., 2008; Zhang and Kitagawa, 2008; Samsonenko et al., 2008; WO 2008/000694; Zhang and Chen, 2009). Accordingly, identifying and developing methods and compositions that overcome these limitations are desirable.